الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Tissue engineering (TE) has recently emerged as a multi-disciplinary technique whereby impaired or mal-functioning organs can be replaced by living organs that have been grown by seeding porous, biocompatible and biodegradable scaffolds with living cells, in a bioreactor, under suitable conditions during which the cells attach to the scaffolds, grow and proliferate, while at the same time, the scaffolds undergo biodegradation to safe byproducts such as CO2 and H2O vapour. In this respect, diversified organs such as skin, bone, heart valve, liver and many others have been formed in the aforementioned way, instead of the harmful earlier autografts and allografts (substitutes from the same patient, and from another donor, in respective order). The aim of the present work was to form scaffolds suitable for bone tissue repair. Accordingly, in this work scaffolds were fabricated from blends of different ratios of corn starch (ST), and cellulose butyrate (CB) which to the best of our knowledge has never been examined before, the latter two were dissolved in dimethylsulfoxide/ dimethyl formamide plus acetone, as an organic solvent, then adding a porogen followed by casting the homogeneous suspension on a glass sheet of a casting knife assembly, into a membrane, coagulating the latter in a water (non-solvent) bath, followed by steeping in water to allow leaching of porogen, so as to leave pores behind forming a porous and highly interconnected scaffold. Alternatively, the casting dope was poured in a petri-dish to produce a thicker scaffold, then treated similarly. Different variables were investigated for their influence on the porosity and strength of the scaffolds, and these were type and mass ratio of polymer, type and ratio of porogen (sodium chloride, sugar (sucrose), polyethylene glycol, or mixture therefrom), concentration of casting dope, and casting technique (on glass sheet or petri-dish), quantity of additive (TiO2) and temperature at which the solvent is sublimed. The scaffolds were subjected to scanning electron microscopic (SEM) examination, and the micrographs revealed highly interconnected porous structures, with optimum pore sizes for cell seeding. Moreover, porosities determined in the lab reached outstanding results in some cases approaching above 95%. Best results were obtained when ST:CB mass ratio was 1:1, while 3:1 and 1:3 mass ratios produced the weakest and less porous scaffolds, respectively.